外源性三磷酸腺苷对肾小管上皮细胞增殖的影响

Exogeneous adenosine triphosphate promotes proliferation of renal tubular epithelial cells

观察外源性三磷酸腺苷（ＡＴＰ）对肾小管上皮细胞株ＬＬＣＰＫ１增殖的影响。方法通过测定３Ｈ－胸腺嘧啶掺入、细胞计数以及细胞内丝裂素活化蛋白激酶活性，并与表皮生长因子（ＥＧＦ）的作用比较。结果发现ＡＴＰ呈浓度依赖性促进细胞的ＤＮＡ合成，并可使细胞计数增加，同时激活细胞内的丝裂素活化蛋白激酶，其作用与ＥＧＦ相似。腺苷与ＡＴＰ有类似作用，但较弱。核苷酸转运蛋白抑制剂对４－硝基苯６－硫基甙并不能抑制ＡＴＰ及腺苷的作用。结论细胞外ＡＴＰ可促进肾小管上皮细胞增殖，并可增强ＥＧＦ的促增殖作用。

Objective To investigate the effect of exogeneous ATP on proliferation of renal tubular epithelial cells(LLC PK 1)and its intracellular mechanisms.Methods DNA synthesis was measured by 3 H thy mindine incorporation,and proliferation was assessed by cell counting.MAP kinase activity was detected by phosphorylate specific substrate MBP.Results Exogeneous ATP(1 1000μmol/L)significantly increased 3H TdR uptake in a concentration dependent manner.It also increased cells proliferation. 100μmol/LATP rapidly activated MAP kinase.The potency of LLC PK 1 proliferation stimulated by ATP was similar to the effect of polypeptide growth factor EGF.Adenosine was less stimulatory effective than ATP.NBTI(50μmol/L),an inhibitor of memberous nucleotide transportor,did not reduce the effects of ATP or Ado on proliferation of these cells.Conclusions Extracellular ATP is a potent mitogen of LLC PK 1 cells,and may promote stimulatory effect of EGF in these cells.This mitogenic effect is unlikely induced by ATP entering cells,but may be mediated by purinergic receptors which activate signaling pathway through MAP kinase cascade.